Various materials have been used as agricultural mulch to enhance plant growth and improve soil, e.g. by conserving water, elevating soil temperature, controlling weeds, and adding organic matter to soils. Such materials have included straw, composted matter, manure, shredded bark and wood, fabric and plastic film. A decision to use mulch is usually based on the ability to achieve improvements over non-mulching agriculture which may require intense cultivation to control weeds and conserve water. Among the common mulch materials, plastic film is preferred for use with many cash crops, e.g. vegetables and ornamentals, due to its low cost and effectiveness in weed control and elevating soil temperature. Among the disadvantages of plastic film are poor distribution of irrigated water and the need to strip the film from fields after the growing season. Moreover, plastic film does not improve soil as organic mulch materials can do when incorporated into the soil after a growing season.
A soil with preferred tilth may comprise nearly equal volumes of air, aggregate, organic matter and water. An advantage of biodegradable mulch is that it can contribute to the a preferred level of tilth when used mulch is incorporated into the soil.